1. Technical Field
The present invention relates to the preservation of blood platelets. Specifically, the present invention concerns (a) blood platelet activation inhibitors, (b) plasma-free platelet storage media containing blood platelet activation inhibitors, and (c) a process for preparing platelets in plasma-free platelet storage media.
2. State of the Art
The use of platelet concentrates in transfusion medicine has become well established during the past thirty years. However, the rapid loss of platelet function during the storage period has greatly complicated management of an effective inventory of platelet concentrates in blood banks. In many settings, the limited shelf life of platelet concentrates has drastically reduced their usage. In order to make platelet transfusion therapy more manageable for blood banks, there has been considerable interest in devising means for diminishing or delaying the loss of platelet function during the storage period. One approach has been in the context of the development of plasma-free platelet storage media. One such media is disclosed in S. Holme, U.S. Pat. No. 4,695,460 (Issued Sept. 22, 1987); see also S. Holme, W. Heaton and M. Courtright, British J. Hematol. 66, 233 (1987). Another such media is disclosed in G. Rock and G. Adams, U.S. Pat. No. 4,447,415 (Issued May 8, 1984); See Also G. Adams and G. Rock, Transfusion 28, 217 (1988); G. Adams et al., Vox Sano. 52, 305 (1987 ); G. Adams et al., Blood 67, 672 (1986). Still another such media is disclosed in S. Murphy et al., Transfusion 26, 568 (1986)(Abstract).
Another approach has focused on the biochemistry of platelet activation. Platelet activation is caused by a broad variety of events, and concludes in platelet lysis and death. Hence, it would be desireable to regulate platelet activation when long storage life of platelet concentrates is desired. A. Bode and D. Miller, Transfusion 25, 461 (1985)(Abstract) report the use of Prostaglandin E-1 (an adenylate cyclase stimulator), theophylline (a phosphodiesterase inhibitor), and either PPACK or Hirudin (Thrombin inhibitors) in combination in platelet concentrates to obtain platelet concentrate shelf lives of up to fifteen days. See also A. Bode and D. Miller, J. Lab. Clin. Med. 111, 118 (1988)(Reviewing attempts to extend platelet shelf life with platelet activation inhibitors); J. Menitove et al., Transfusion 28, 56 (1988)(Reviewing attempts to extend platelet shelf life with platelet activation inhibitors). The challenge in this line of research has been to develop the unique combination of platelet activators which will most effectively extend platelet shelf life.
The present invention is based on our continued research into means for extending platelet shelf life.